Fastening element, particularly for blind rivets

Abstract

The invention describes a fastening element ( 1 ), in particular for blind riveting, having a sethead ( 4 ), a deformation segment ( 2 ) and a shank end ( 3 ), the deformation segment ( 2 ) being arranged between the sethead ( 4 ) and the shank end ( 3 ), and the fastening element ( 1 ) being hollow inside, optionally with a mandrel ( 7 ) inside the fastening element ( 1 ), comprising a mandrel head ( 23 ) and a mandrel foot ( 24 ) tension-resistantly connected at least to the shank end ( 3 ). The shank end ( 3 ) is provided with a punch edge ( 6 ) extending essentially along the outermost periphery of the shank end ( 3 ) and formed by a peripheral surface ( 26 ) and a face ( 25 ) of the shank end ( 3 ). In the center of the face ( 25 ), a projection is provided, protruding from the plane in which the punch edge ( 6 ) lies on the side away from the sethead ( 4 ). The projection may be formed by a conical or pyramidal surface.

1 . Fastening element ( 1 ), in particular for blind riveting, having a hollow shank ( 27 ) comprising a sethead ( 4 ) at its free end, having a deformation segment ( 2 ) to form a closure head, and having a connecting segment ( 28 ) formed inside the shank ( 27 ) and serving to form a tension-resistant connection to a mandrel ( 7 ), in particular the foot ( 24 ) of a mandrel ( 7 ), the shank end ( 3 ) opposed to the sethead ( 4 ) being provided with a punch edge ( 6 ) extending essentially along the outermost periphery of the shank ( 27 ) and formed by a peripheral surface ( 26 ) and a face ( 25 ) of the shank end ( 3 ), and a projection being provided in the center of the face ( 25 ) protruding from the plane in which the punch edge ( 6 ) lies on the side away from the sethead ( 4 ).  
   
   
       2 . Fastening element ( 1 ), in particular for blind riveting, having a hollow shank ( 27 ) comprising a sethead ( 4 ) at its free end, having a deformation segment ( 2 ) to form a closure head, having a mandrel ( 7 ) inside the shank ( 27 ), comprising a mandrel head ( 23 ) and a mandrel foot ( 24 ), the mandrel foot ( 24 ) being at least tension-resistantly connected to a shank end ( 3 ) opposed to the sethead ( 4 ), the shank end ( 3 ) comprising a punch edge ( 6 ) extending essentially along the outermost periphery of the shank ( 27 ) and formed by a peripheral surface ( 26 ) and a face ( 25 ) of the shank end ( 3 ), and a projection being provided in the center of the face ( 25 ), protruding from the plane in which the punch edge ( 6 ) lies on the side away from the sethead ( 4 ).  
   
   
       3 . Fastening element according to  claim 1 , characterized in that the shank end ( 3 ) opposed to the sethead ( 4 ) is open and the projection is arranged at the foot ( 24 ) of the mandrel.  
   
   
       4 . Fastening element according to  claim 1 , characterized in that the shank end ( 3 ) opposed to the sethead ( 4 ) is closed and forms the projection with a bottom ( 35 ).  
   
   
       5 . Fastening element according to  claim 1 , characterized in that, inside the shank ( 27 ), a connecting segment ( 28 ) is formed, serving to form a tension-resistant connection with the mandrel ( 7 ), in particular the foot ( 24 ) of the mandrel ( 7 ).  
   
   
       6 . Fastening element ( 1 ), in particular for blind riveting, having a hollow shank ( 27 ) comprising a sethead ( 4 ) at its free end, having a deformation segment ( 2 ) to form a closure head, having a mandrel ( 7 ) inside the shank ( 27 ) comprising a mandrel head ( 23 ) and a mandrel foot ( 24 ), the mandrel foot ( 24 ) being tension-resistantly connected at least to a shank end ( 3 ) opposed to the sethead ( 4 ) and comprising a punch edge ( 6 ) extending essentially along the outermost periphery of the mandrel foot ( 24 ), and formed by a peripheral surface ( 34 ) and a face ( 32 ) of the mandrel foot ( 24 ), and a projection ( 33 ) being provided in the center of the face ( 32 ), protruding from the plane in which the punch edge ( 6 ) lies on the side away from the sethead ( 4 ).  
   
   
       7 . Fastening element ( 1 ) according to  claim 1 , characterized in that the projection ( 33 ) is offset from the face by a step.  
   
   
       8 . Fastening element ( 1 ) according to  claim 1 , characterized in that the face ( 25 ) passes smoothly from the punch edge ( 6 ) into the projection.  
   
   
       9 . Fastening element ( 1 ) according to  claim 1 , characterized in that the height of the projection measured from the plane in which the punch edge lies is 2.5% to 5% of the diameter, or mean diameter, of the punch edge.  
   
   
       10 . Fastening element ( 1 ) according to  claim 1 , characterized in that the face ( 25 ,  32 ) has a shape conforming to a conical or pyramidal surface tapering down in the punching direction.  
   
   
       11 . Fastening element ( 1 ) according to  claim 1 , characterized in that the cross-section of the fastening element ( 1 ) is substantially circular.  
   
   
       12 . Fastening element ( 1 ) according to  claim 1 , characterized in that the face ( 25 ) and the peripheral surface ( 26 ) make an included angle of 93° to 96° with each other.  
   
   
       13 . Fastening element ( 1 ) according to  claim 1 , characterized in that the cross-section of the fastening element ( 1 ) is substantially polygonal.  
   
   
       14 . Fastening element ( 1 ) according to  claim 1 , characterized in that the mandrel head ( 23 ) is widened.  
   
   
       15 . Fastening element ( 1 ) according to  claim 1 , characterized in that the shank end ( 3 ) or the mandrel foot ( 24 ), at least in the region of the punch edge ( 6 ), is stronger, in particular hardened.  
   
   
       16 . Fastening element according to  claim 2 , characterized in that the shank end ( 3 ) opposed to the sethead ( 4 ) is open and the projection is arranged at the foot ( 24 ) of the mandrel.  
   
   
       17 . Fastening element according to  claim 2 , characterized in that the shank end ( 3 ) opposed to the sethead ( 4 ) is closed and forms the projection with a bottom ( 35 ).  
   
   
       18 . Fastening element according to  claim 2 , characterized in that, inside the shank ( 27 ), a connecting segment ( 28 ) is formed, serving to form a tension-resistant connection with the mandrel ( 7 ), in particular the foot ( 24 ) of the mandrel ( 7 ).  
   
   
       19 . Fastening element ( 1 ) according to  claim 2 , characterized in that the projection ( 33 ) is offset from the face by a step.  
   
   
       20 . Fastening element ( 1 ) according to  claim 2 , characterized in that the face ( 25 ) passes smoothly from the punch edge ( 6 ) into the projection.  
   
   
       21 . Fastening element ( 1 ) according to  claim 2 , characterized in that the height of the projection measured from the plane in which the punch edge lies is 2.5% to 5% of the diameter, or mean diameter, of the punch edge.  
   
   
       22 . Fastening element ( 1 ) according to  claim 2 , characterized in that the face ( 25 ,  32 ) has a shape conforming to a conical or pyramidal surface tapering down in the punching direction.  
   
   
       23 . Fastening element ( 1 ) according to  claim 2 , characterized in that the cross-section of the fastening element ( 1 ) is substantially circular.  
   
   
       24 . Fastening element ( 1 ) according to  claim 2 , characterized in that the face ( 25 ) and the peripheral surface ( 26 ) make an included angle of 93° to 96° with each other.  
   
   
       25 . Fastening element ( 1 ) according to  claim 2 , characterized in that the cross-section of the fastening element ( 1 ) is substantially polygonal.  
   
   
       26 . Fastening element ( 1 ) according to  claim 2 , characterized in that the mandrel head ( 23 ) is widened.  
   
   
       27 . Fastening element ( 1 ) according to  claim 2 , characterized in that the shank end ( 3 ) or the mandrel foot ( 24 ), at least in the region of the punch edge ( 6 ), is stronger, in particular hardened.  
   
   
       28 . Fastening element ( 1 ) according to  claim 6 , characterized in that the projection ( 33 ) is offset from the face by a step.  
   
   
       29 . Fastening element ( 1 ) according to  claim 6 , characterized in that the face ( 25 ) passes smoothly from the punch edge ( 6 ) into the projection.  
   
   
       30 . Fastening element ( 1 ) according to  claim 6 , characterized in that the height of the projection measured from the plane in which the punch edge lies is 2.5% to 5% of the diameter, or mean diameter, of the punch edge.  
   
   
       31 . Fastening element ( 1 ) according to  claim 6 , characterized in that the face ( 25 ,  32 ) has a shape conforming to a conical or pyramidal surface tapering down in the punching direction.  
   
   
       32 . Fastening element ( 1 ) according to  claim 6 , characterized in that the cross-section of the fastening element ( 1 ) is substantially circular.  
   
   
       33 . Fastening element ( 1 ) according to  claim 6 , characterized in that the face ( 25 ) and the peripheral surface ( 26 ) make an included angle of 93° to 96° with each other.  
   
   
       34 . Fastening element ( 1 ) according to  claim 6 , characterized in that the cross-section of the fastening element ( 1 ) is substantially polygonal.  
   
   
       35 . Fastening element ( 1 ) according to  claim 6 , characterized in that the mandrel head ( 23 ) is widened.  
   
   
       36 . Fastening element ( 1 ) according to  claim 6 , characterized in that the shank end ( 3 ) or the mandrel foot ( 24 ), at least in the region of the punch edge ( 6 ), is stronger, in particular hardened.